Valve assembly for air maintenance tire

ABSTRACT

An air maintenance tire and air pump assembly includes a sidewall and a tire cavity for maintaining pressure; an elongate tubular air passageway enclosed within a flexing region of the sidewall, air passageway, the air passageway operably closing segment by segment in reaction to induced forces from the tire flexing region as the flexing region of the tire wall rotates adjacent a rolling tire footprint, the elongate air passageway having at least one check valve device seated within the axial air passageway; and a relief valve assembly comprising a chamber body, a valve, a piston, and a silicone ring, the valve having a valve body and a valve head, the valve head, deforming to release over-pressurized air from the tire cavity to atmosphere.

FIELD OF THE INVENTION

The present invention relates generally to air maintenance systems for apneumatic tire and, more specifically, to such systems that affix an airpump apparatus to a pneumatic tire which maintains air pressure withinthe pneumatic tire as the tire rotates under load.

BACKGROUND OF THE INVENTION

Normal air diffusion reduces tire pressure over time. The natural stateof pneumatic tires is under inflated. Accordingly, drivers mustrepeatedly act to maintain tire pressures or they will see reduced fueleconomy, tire life, and/or reduced vehicle braking and handlingperformance. Tire pressure monitoring systems have been proposed to warndrivers when tire pressure is significantly low. Such systems, however,remain dependant upon the driver taking remedial action when warned tore-inflate a pneumatic tire to the recommended pressure. It is adesirable, therefore, to incorporate a self-inflating feature within apneumatic tire that will self-inflate the tire in order to compensatefor any reduction in tire pressure over time without the need for driverintervention.

SUMMARY OF THE PRESENT INVENTION

An air maintenance tire and air pump assembly in accordance with thepresent invention includes a tire having a tread region and first andsecond sidewalls extending from the tread region and a tire cavity formaintaining pressure; an elongate tubular air passageway enclosed withina flexing region of a tire wall, the air passageway having an air inletportal operable to admit air into the air passageway and an outletportal spaced apart from the inlet portal operable to withdrawpressurized air from the air passageway, the air passageway operablyclosing segment by segment in reaction to induced forces from the tireflexing region as the flexing region of the tire wall rotates adjacent arolling tire footprint, the elongate air passageway having at least onecheck valve device seated within the axial air passageway; and a reliefvalve assembly comprising a chamber body, a valve, a piston, and asilicone ring, the valve having a valve body and a valve head, the valvehead, deforming to release over-pressurized air from the tire cavity toatmosphere.

According to another aspect of the assembly, the valve head is encasedby an elastic material and closes an orifice of the chamber body therebyallowing air escape to atmosphere.

According to still another aspect of the assembly, the piston is movablefor extension through the chamber body from an internal cavity of thevalve body to an internal cavity of the chamber body.

According to yet another aspect of the assembly, a gasket seals aninterface between the piston and the sleeve.

According to still another aspect of the assembly, the valve body istubular with the sleeve being partially radially inserted into the valvebody.

According to yet another aspect of the assembly, the sleeve includes aradial bore defining an air way extending between an internal cavity ofthe chamber body and an internal cavity of the valve body.

According to still another aspect of the assembly, the sleeve and thepiston partially define a valve internal cavity.

According to yet another aspect of the assembly, the silicone ring isfitted to an end of the piston.

According to still another aspect of the assembly, the piston and thesilicone ring are entirely within an internal cavity of the valve bodyand, simultaneously, flow through a radial bore within the sleeve isunobstructed.

According to yet another aspect of the assembly, pressure within thechamber body and the valve body are equalized by radial clearancebetween the sleeve and the piston.

According to still another aspect of the assembly, the piston andsilicone ring are entirely within the sleeve and air through a radialbore of the sleeve is obstructed.

According to yet another aspect of the assembly, pressure within thechamber body and the valve body are independent and separate.

According to still another aspect of the assembly, axial movement of thepiston and the silicone ring into the sleeve causes a pressure decreasein the valve body such that a release vent of the tire cavity to thechamber body is no longer completely blocked by the valve head.

According to yet another aspect of the assembly, the valve head ismaintained in a deformed condition.

According to still another aspect of the assembly, the chamber bodyincludes radial outlets to atmosphere.

According to yet another aspect of the assembly, a supplemental spaceraxially adjacent to the sleeve mitigate twisting during assembly.

A second air maintenance tire and air pump assembly, for use with thepresent invention, includes a tire; an elongate tubular air passagewayenclosed within a flexing region of a tire wall, the air passagewayhaving an air inlet portal operable to admit air into the air passagewayand an outlet portal spaced apart from the inlet portal operable towithdraw pressurized air from the air passageway, the air passagewayoperably closing segment by segment in reaction to induced forces fromthe tire flexing region as the flexing region of the tire wall rotatesopposite to a rolling tire footprint. Multiple spaced apart check valvedevices are seated within and along the axial air passageway, dividingthe air passageway into multiple passageway segments. Each check valvedevice has an external dimension and configuration operable tosubstantially occupy the air passageway. A valve gate, such as amembrane, allows pressurized air to directionally pass through the checkvalve device from an upstream passageway segment to a downstreampassageway segment. The valve gate in a closed position prohibits airfrom passing in an opposite direction through the check valve body fromthe downstream passageway segment to the upstream passageway segment.

In another aspect of the second assembly, the air passageway mayalternatively be configured as an integrally formed passageway withinthe tire sidewall or as an axial passage provided by a flexible air tubethat is assembled to the tire in a post-cure procedure.

In still another aspect of the second assembly, each check valve deviceis configured as a tubular body closely received within the airpassageway, the tubular body having outwardly projecting retentionbarb(s) for securing the tubular body at a preferred location within theair passageway. The tubular body houses a flexible membrane member whichserves as the valve gate. The membrane opens along a slit to admitpressurized air from one side of the check valve device to an oppositeside.

In yet another aspect of the second assembly, the check valve devicesmay be positioned and spaced along a continuous air passageway extendingbetween the inlet and outlet portals, or, alternatively, serve toconnect air tube segments together in a splicing check valveconfiguration.

Definitions

“Aspect ratio” of the tire means the ratio of its section height (SH) toits section width (SW) multiplied by 100 percent for expression as apercentage.

“Asymmetric tread” means a tread that has a tread pattern notsymmetrical about the center plane or equatorial plane EP of the tire.

“Axial” and “axially” means lines or directions that are parallel to theaxis of rotation of the tire.

“Chafer” is a narrow strip of material placed around the outside of atire bead to protect the cord plies from wearing and cutting against therim and distribute the flexing above the rim.

“Circumferential” means lines or directions extending along theperimeter of the surface of the annular tread perpendicular to the axialdirection.

“Equatorial Centerplane (CP)” means the plane perpendicular to thetire's axis of rotation and passing through the center of the tread.

“Footprint” means the contact patch or area of contact of the tire treadwith a flat surface at zero speed and under normal load and pressure.

“Groove” means an elongated void area in a tread that may extendcircumferentially or laterally about the tread in a straight, curved, orzigzag manner. Circumferentially and laterally extending groovessometimes have common portions. The “groove width” is equal to treadsurface area occupied by a groove or groove portion, the width of whichis in question, divided by the length of such groove or groove portion;thus, the groove width is its average width over its length. Grooves maybe of varying depths in a tire. The depth of a groove may vary aroundthe circumference of the tread, or the depth of one groove may beconstant but vary from the depth of another groove in the tire. If suchnarrow or wide grooves are substantially reduced depth as compared towide circumferential grooves which the interconnect, they are regardedas forming “tie bars” tending to maintain a rib-like character in treadregion involved.

“Inboard side” means the side of the tire nearest the vehicle when thetire is mounted on a wheel and the wheel is mounted on the vehicle.

“Lateral” means an axial direction.

“Lateral edges” means a line tangent to the axially outermost treadcontact patch or footprint as measured under normal load and tireinflation, the lines being parallel to the equatorial centerplane.

“Net contact area” means the total area of ground contacting treadelements between the lateral edges around the entire circumference ofthe tread divided by the gross area of the entire tread between thelateral edges.

“Non-directional tread” means a tread that has no preferred direction offorward travel and is not required to be positioned on a vehicle in aspecific wheel position or positions to ensure that the tread pattern isaligned with the preferred direction of travel. Conversely, adirectional tread pattern has a preferred direction of travel requiringspecific wheel positioning.

“Outboard side” means the side of the tire farthest away from thevehicle when the tire is mounted on a wheel and the wheel is mounted onthe vehicle.

“Peristaltic” means operating by means of wave-like contractions thatpropel contained matter, such as air, along tubular pathways.

“Radial” and “radially” means directions radially toward or away fromthe axis of rotation of the tire.

“Rib” means a circumferentially extending strip of rubber on the treadwhich is defined by at least one circumferential groove and either asecond such groove or a lateral edge, the strip being laterallyundivided by full-depth grooves.

“Sipe” means small slots molded into the tread elements of the tire thatsubdivide the tread surface and improve traction, sipes are generallynarrow in width and close in the tires footprint as opposed to groovesthat remain open in the tire's footprint.

“Tread element” or “traction element” means a rib or a block elementdefined by having a shape adjacent grooves.

“Tread Arc Width” means the arc length of the tread as measured betweenthe lateral edges of the tread.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described by way of example and with reference tothe accompanying drawings in which:

FIG. 1 is a schematic sectional view of a valve in accordance with thepresent invention.

FIG. 2 is a schematic detail of the valve of FIG. 1 under a firstcondition.

FIG. 3 is a schematic detail of the valve of FIG. 1 under a secondcondition.

FIG. 4 is a schematic perspective sectional view of the valve of FIG. 1.

DETAILED DESCRIPTION OF EXAMPLES OF THE PRESENT INVENTION

A pneumatic tire and air maintenance pump assembly (forming an “airmaintenance tire” or “AMT”) in accordance with the present invention mayinclude an example pneumatic tire and an example vein pump assembly asset forth in U.S. Ser. No. 13/659,080 filed on Oct. 24, 2012 and ownedby The Goodyear Tire & Rubber Company, incorporated herein in itsentirety by reference. The general operation of one example peristalticpump for use in an example pneumatic tire is described in U.S. Pat. Nos.8,113,254 and 8,042,586, both filed on Dec. 12, 2009, and issued on Feb.14, 2012 and Oct. 25, 2011, respectively, and owned by The Goodyear Tire& Rubber Company, both also incorporated herein in their entirety byreference.

The pneumatic tire may be constructed to provide a tread region, a pairof sidewalls extending from opposite bead areas to the tire treadregion. The pneumatic tire may enclose a tire cavity. The airmaintenance assembly may include an elongate air tube that encloses anannular passageway. The tube may be formed of a resilient, elastomericflexible material, such as plastic or rubber compounds and compositesthat may withstand repeated deformation cycles wherein the tube isdeformed into a flattened condition subject to external force/load and,upon removal of such force, returns to an original condition generallycircular in cross-section. The tube may have a diameter sufficient tooperatively pass a volume of air for the purpose of maintaining airpressure within the tire cavity. One example tube may follow a 180degree semi-circular path. However, other configurations may also beemployed.

The example air maintenance vein pump assembly may further include aninlet device and an outlet device spaced apart approximately 180 degreesat respective opposite end locations of the air tube. The outlet devicemay have a T-shaped configuration in which T-forming sleeves connect toan end of the tube and an outlet conduit may conduct air from the tubeto the tire cavity. The inlet device may likewise have a T-shapedconfiguration, connecting to an opposite end of the tube and having aninlet conduit which intakes outside air into the tube passageway. Thepatents and pending application incorporated herein above provideexamples of the outlet and inlet devices. Commercially available valvemechanisms for controlling air intake into the tube and air outlet fromthe tube into the cavity may be used within the inlet and outletdevices.

The air tube, inlet device, and the outlet device may be positionedwithin an appropriately complementarily configured channel within one ofthe tire sidewalls. As the example pneumatic tire rotates, under load, afootprint may be formed against a ground surface. A compressive forcemay thus be directed into the pneumatic tire from the footprint and actto flatten a segment of the air tube and passageway. As the tire rotatesfurther, portions of the air tube and passageway may be sequentiallyflattened and pump air in a direction toward the tire cavity. Flatteningof the tube, segment by segment, or portion by portion, thereby forcesair from the inlet along the passageway until the pressurized air isdirected from the outlet and into the tire cavity. An appropriate valvemechanism at the outlet may vent air in the event that the tire cavitypressure exceeds the recommended tire pressure. Typically, pumping ofair may occur for one-half the revolution of the tire with the 180degree air tube configuration.

An alternative 360 degree air tube may functions as described above,other than air being pumped along the air tube in one direction for anentire 360 degree revolution of the pneumatic tire. In an examplepneumatic tire with two 180 degree peristaltic tubes, the pump mayfunction in either direction of tire rotation. The two air tubes mayeach be operational in a respective direction of rotation to pump airinto the tire cavity.

A plurality of check valves may be provided for placement in thepassageway of the air tube. The check valves may include a cylindricalvalve body composed of any suitable rigid or semi-rigid material. Thevalve body may have a rounded forward end rim. An array of outwardlydirected retention ribs or flanges may be spaced apart along a surfaceof the valve body, each retention rib angling to the rear of the valvebody. A flexible, elastomeric membrane member may be inserted into acentral through-passage of the valve body. The membrane member mayinclude a cylindrical membrane body captured within the valve body bymeans of turning in end flanges of the valve body. The membrane membermay further include a central projecting nose with a slit there-through.The nose may form a gate through which pressurized air may flow in aforward direction while preventing back flow of air through the checkvalve in a rearward direction.

As stated above, multiple check valves may be inserted into the axialpassageway of the tube. The multiple check valves may occupy spacedapart, respective locations within the tube in an orientation whichfacilitates a flow of pressurized air in a forward direction from theinlet to the outlet, but which prevents a back flow of pressurized airin the reverse direction. A pressurized air source may be positioned toinject pressurized air into the passageway, thereby radially expandingthe tube such that the passageway flexes to a temporary, oversizeddiameter. A stopper may be inserted into a forward end of the tube toprevent the pressurized air from escaping to atmosphere.

At the check valve location in the passageway, a clamping collar may beaffixed over the tube and may exert a radial force on the tube, therebypreventing the tube from expanding at that location. Thereafter, a checkvalve may be inserted into an open end of the tube with the membranemember, or gate, opening toward the outlet end of the tube. A rod maypush the check valve through the expanded tube until it reaches itsintended location within passageway.

The clamping collar may then be removed and relocated down the axiallength of the tube to a second check valve location. The second checkvalve may be positioned at the open end of the tube and pushed by rodthrough the diametrically expanded tube to the intended second checkvalve location within the passageway. This procedure may be repeateduntil all of the check valves are in place within the passageway. Oncethe pressurized air flow is withdrawn from the passageway, the tube mayelastically radially contract to its original, unexpanded condition. Thetube by its resilient radial contraction thereby captures each placedcheck valve and exerts a radial compression force on the check valvebodies to hold the check valves in their intended locations within thepassageway. With the radial contraction of the tube, the retentionflanges or barbs on the sides of the cylindrical valve body of eachcheck valve may engage the sidewalls of the tube, and thus function, inconjunction with the tube radial clamping force on the check valves, toretain the check valves in their intended locations.

Multiple secondary retention clamps, each in the form of a cylindricalcollar, may be deployed over respective locations along the tube wherethe check valves have been positioned. The clamps may be formed offlexible material, such as plastic or metal. The clamps may be openableto facilitate receipt of the tube through each clamp. Subsequently, theclamps may be closed into a circular configuration, overlap lockingflanges, and engage each clamp in a closed circular configuration overthe tube. The opening through the clamps may be sized nominally smallerthan the tube diameter such that the closed clamps squeeze the tuberadially inward over the check valves.

The resilient, radially directed force on the exterior of the tube,combined with engagement of each check valve's retention flanges withthe interior of the tube and the clamps, may provide redundant means forretaining each check valve in its intended location within thepassageway. Opening and closing of the check valves during operation ofthe pump assembly will accordingly not act to dislocate any of the checkvalves from their positions within the tube.

An alternatively configured check valve may have a splice configuration.The check valve may have an elongate valve body (cylindrical or othershape). First and second arrays of retention flanges or barbs may beprovided, the first array at a forward location along the elongate bodyand the second array at a rearward location along the elongate body. Theelongate body may have a centered membrane insert configured to operatein the manner described above. The elongate body may splice two segmentsof tube together. An end of each of the tubes may attach at a respectiveend of the elongate body, whereupon the barb arrays may engage internalsidewalls of the tube.

Upon completed assembly of the check valves with the tube, the tube maybe inserted into a complementarily configured channel formed within atire sidewall. The lower sidewall region above, or adjacent, the beadregion may flex sufficiently to allow for the segment by segment airpumping action by the tube described above. If desired, higher locationson the tire sidewall may be used as the location for the tube withoutdeparting from the present invention. One or both of the tire sidewallsmay contain an air pumping tube, if desired, and the system may beconfigured in a 180 degree, 360 degree, or dual 180 degree tubeconfiguration.

While the tube may be generally of circular cross-section, alternativetube sectional configurations may be used (e.g., ellipse,mushroom-shape, square, triangle pentagon, hexagon, octagon, etc.). Thetube may fit into a sidewall groove with a cap abutting an outersidewall surface. The check valves may have a complementary externalshape and configuration to the shape of the air passageway into whichthe check valves are placed. Likewise, the clamping mechanisms may beconfigured to fit over the tube configuration in order to impose aradial clamping force on a check valve.

The check valves between the tube segments may open only in a forwarddirection between air inlet and air outlet and do not allow any backflow of air within the tube in a reverse direction. A series of segmentsmay be strung together with adjacent segments separated by a check valve(e.g., a vein-type system). The adjoining segments may sequentially pumpair, segment to segment, as the tire-mounted tube moves adjacent arolling tire footprint. The check valves thus prevent a back flow of airand operate to increase the pumping efficiency of the vein/tube system.Consequently, the vein/tube volumetric size may be relatively smallwithout compromising achievement of the requisite air pumping volumenecessary for maintaining the tire at its rated pressure. The checkvalve and vein segment construction may improve the air pressure levelat the outlet beyond what would be attained from a single segment,non-check valve, tube of equal length.

An adjustable valve assembly 10 (FIG. 1) in accordance with the presentinvention, for use with systems such as the example described above, maybe in a closed position when the air pressure of the tire cavity isbelow a selected pressure and in an opened position when the airpressure is above the selected pressure (e.g., pressure relief, reliefvalve, etc.). The selected pressure may be adjustable by the valveassembly 10. When a selected pressure is exceeded in the tire cavity,the valve assembly 10 may open thereby allowing exhaust air to anotherlocation, and eventually to atmosphere. The adjustable valve assembly 10may define an internal circumferential channel with both extremities:one in the tire chamber and the other at the external part of the tire.

The adjustable valve assembly 10 may include a chamber body 20, a valve50, a sleeve 70, a piston 80, and a silicone ring 90. The valve 50 mayinclude a valve body and a valve head 54 encased by an elastic materialand closing an orifice 110 of the chamber body 20 thereby allowing airescape, or air pressure relief, when the valve is in an opened position.A part of the movable piston 80 may extend through the chamber body 20from an internal cavity 56 of the valve body 50 to an internal cavity 22of the chamber body 20 and be sealed by a gasket or gaskets 120, such asgaskets, o-rings, etc. The chamber internal cavity 22 may be pressurizedto a predetermined air pressure. The valve body 50 may be tubular withpart of the sleeve 70 partially inserted into the valve body (FIG. 1).

The valve body 50 may include a bore 72 radially drilled to define anair way extending between the chamber internal cavity 22 and the valveinternal cavity 56. The sleeve 70 and the piston 80 may partially definethe valve internal cavity 56. A silicone ring 90 may be fixed/fitted toan end of the piston 80 opposite the o-ring(s) 120.

When the piston 80 and silicone ring 90 are entirely within the valveinternal cavity 56, the bore 72 between the chamber internal cavity 22and the valve internal cavity may be open. In this instance, thepressure within the chamber internal cavity 22 and the valve internalcavity 56 may be equalized by radial clearance between the sleeve 70 andthe piston 80 (FIG. 2). When the piston 80 and silicone ring 90 areentirely within the sleeve 70, air through the bore 72 may be blocked.In this instance, the pressure within the chamber internal cavity 22 andthe valve internal cavity 56 may be independent and separate (FIG. 3).

When the chamber internal cavity 22 has a first pressure (FIG. 2), axialmovement of the piston 80 and the silicone ring 90 into the sleeve 70may cause a pressure decrease/vacuum in the valve internal cavity 56such that a pump connection, or release vent, 110 of the tire cavity tothe chamber internal cavity 22 is no longer completely blocked by thevalve head 54 (e.g., deformation of the elastic/elastomeric valve head,etc.). Thus, while the piston 80 and silicone ring 90 remain in thisposition, the pressure in the chamber internal cavity 22 may not exceedthe first pressure even if an external operation, such as by an AMTassembly as described above, attempts to increase the pressure in thechamber internal cavity.

The valve 50 may be balanced at the first pressure and the smaller airpressure in the valve internal cavity 56 may maintain the valve head ina deformed condition. Air may escape the chamber internal cavity 22through an exhaust vent 130 to atmosphere. The exhaust vent 130 may beone or more radial outlets from the chamber internal cavity 22.

Once the pressure in the valve internal cavity 56 is at its desiredvalue, the assembly 10 may be used in coordination with an AMT assembly,such as the example described above. At this time, the valve head 54 mayclose the exhaust vent 110. The valve head 54 may be plastic, resin,silicone, and/or other suitable material.

The assembly 10 may be adjusted by insertion into an adjustment box (notshown). The box may have two ports, one to inject compressed air at adetermined pressure and the other to detect an air leak. Afterpressurizing the box to the predetermined pressure, a movement of thepiston 80 away from the exhaust vent 110 may be initiated until an airleak is detected. The piston 80 may then be locked into position by oneor more set screws 140 (FIG. 4). The assembly 10 may now be in anadjusted state for the predetermined pressure. The assembly 10 may nowbe removed from the box and assembled with a pneumatic tire. Asupplemental cylindrical gasket/spacer 150 replacing the o-rings 120,may be added axially adjacent to the sleeve 70 for mitigating twistingduring assembly. One of ordinary skill in the art will appreciate thatthe subject assembly in a pneumatic tire achieves significant advantageover a pneumatic tire without the assembly.

Variations in the present invention are possible in light of thedescription of it provided herein. While certain representativeembodiments and details have been shown for the purpose of illustratingthe subject invention, it will be apparent to those skilled in this artthat various changes and modifications can be made therein withoutdeparting from the scope of the subject invention. It is, therefore, tobe understood that changes can be made in the particular embodimentsdescribed which will be within the full intended scope of the inventionas defined by the following appended claims.

What is claimed:
 1. An air maintenance tire and air pump assemblycomprising: a tire having a tread region and first and second sidewallsextending from the tread region and a tire cavity for maintainingpressure; an elongate tubular air passageway enclosed within a flexingregion of a tire wall, the air passageway having an air inlet portaloperable to admit air into the air passageway and an outlet portalspaced apart from the inlet portal operable to withdraw pressurized airfrom the air passageway, the air passageway operably closing segment bysegment in reaction to induced forces from the tire flexing region asthe flexing region of the tire wall rotates adjacent a rolling tirefootprint; the elongate air passageway having at least one check valvedevice seated within the axial air passageway; and a relief valveassembly comprising a chamber body, a valve, a piston, and a siliconering, the valve having a valve body and a valve head, the valve head,deforming to release over-pressurized air from the tire cavity toatmosphere.
 2. The assembly as set forth in claim 1 wherein the valvehead is encased by an elastic material and closes an orifice of thechamber body thereby allowing air escape to atmosphere.
 3. The assemblyas set forth in claim 1 wherein the piston is movable for extensionthrough the chamber body from an internal cavity of the valve body to aninternal cavity of the chamber body.
 4. The assembly as set forth inclaim 1 further including a gasket for sealing an interface between thepiston and the sleeve.
 5. The assembly as set forth in claim 1 whereinthe valve body is tubular with the sleeve being partially radiallyinserted into the valve body.
 6. The assembly as set forth in claim 1wherein the valve body includes a radial bore defining an air wayextending between an internal cavity of the chamber body and an internalcavity of the valve body.
 7. The assembly as set forth in claim 1wherein the sleeve and the piston partially define a valve internalcavity.
 8. The assembly as set forth in claim 1 wherein the siliconering is fitted to an end of the piston.
 9. The assembly as set forth inclaim 1 wherein the piston and the silicone ring are entirely within aninternal cavity of the valve body and, simultaneously, flow through aradial bore within the sleeve is unobstructed.
 10. The assembly as setforth in claim 1 wherein pressure within the chamber body and the valvebody are equalized by radial clearance between the sleeve and thepiston.
 11. The assembly as set forth in claim 1 wherein the piston andsilicone ring are entirely within the sleeve and air through a radialbore of the sleeve is obstructed.
 12. The assembly as set forth in claim1 wherein pressure within the chamber body and the valve body areindependent and separate.
 13. The assembly as set forth in claim 1wherein axial movement of the piston and the silicone ring into thesleeve causes a pressure decrease in the valve body such that a releasevent of the tire cavity to the chamber body is no longer completelyblocked by the valve head.
 14. The assembly as set forth in claim 1wherein the valve head is maintained in a deformed condition.
 15. Theassembly as set forth in claim 1 wherein the chamber body includesradial outlets to atmosphere.
 16. The assembly as set forth in claim 1further including a supplemental spacer axially adjacent to the sleevefor mitigating twisting during assembly.